Portable spray device

Abstract

The present invention relates to a portable spraying device (1) for discharging a fluid, in particular an agricultural formulation, having a container (2) for holding the fluid, a pump (15), which is in fluid connection with the container (2), for pumping the fluid out of the container (2), a spray gun (21), which comprises a spray opening (27) and an electrically controllable application valve (20) for opening and closing a passage to the spray opening (27), an application line (17), which establishes a fluid connection between the pump (15) and the spray gun (21). The spraying device (1) according to the invention is distinguished by a pressure sensor (19), which is arranged in the application line (17), for detecting the fluid pressure in the application line (17), and an electric control device (28), which is coupled to the application valve (20) and the pressure sensor (19) in terms of data transmission, by means of which device an electric control signal for opening the application valve (20) for a certain predetermined time interval and for closing the application valve (20) on expiry of the time interval can be produced in accordance with the fluid pressure detected by means of the pressure sensor (19), with the result that a defined volume of the fluid is discharged via the spray opening (27).

The invention claimed is: 
     
       1. A portable spraying device for discharging a fluid, the portable spraying device comprising:
 a container for holding the fluid, 
 a pump, which is in fluid connection with the container, for pumping the fluid out of the container, 
 a spray gun, which comprises a spray opening and an electrically controllable application valve for opening and closing a passage to the spray opening, 
 an application line, which establishes a fluid connection between the pump and the spray gun, 
 a pressure sensor, which is arranged in the application line, for detecting the fluid pressure in the application line, 
 an electric control device, which is coupled to the application valve and the pressure sensor in terms of data transmission, wherein the electric device is adapted to deliver an electric control signal for opening the application valve for a certain predetermined time interval and for closing the application valve on expiry of the time interval in accordance with the fluid pressure detected by means of the pressure sensor, with the result that a defined volume of the fluid is discharged via the spray opening, and 
 an electrically controllable valve, which is arranged between the container and the pump, and which is coupled to the control device in terms of data transmission, wherein ambient air is drawn in by the pump in a first position of the valve, such that ambient air passes through the valve; and fluid is drawn in from the container in a second position of the valve, such that fluid passes through the valve; 
 wherein the application valve is a shutoff valve with a shutoff body for closing a valve passage and the application valve has a valve spring which exerts a force on the shutoff body in the direction of a valve seat in order to close the valve passage or which exerts a force on the shutoff body in the direction away from the valve seat in order to open the valve passage, 
 wherein the application valve has a valve chamber which is in fluid connection with the application line, and 
 wherein the shutoff body is arranged relative to the valve chamber and the valve seat in such a way that a fluid pressure on the part of a fluid in the valve chamber presses the shutoff body onto the valve seat. 
 
     
     
       2. The portable spraying device of  claim 1 , wherein the electric control device is coupled to the pump in terms of data transmission, and the pump can be controlled by means of the control device in such a way that a predetermined fluid pressure is applied to the application valve when the application valve is closed. 
     
     
       3. The portable spraying device of  claim 1 , wherein the application valve can be controlled by means of the control device in such a way that the defined volume of the fluid which is discharged via the spray opening is less than 1 ml. 
     
     
       4. The portable spraying device of  claim 1 , wherein the valve spring is a leaf spring or a spring disk. 
     
     
       5. The portable spraying device of  claim 1 , wherein the application valve has a rated size in a range of from 0.5 mm to 1.5 mm. 
     
     
       6. The portable spraying device of  claim 1 , wherein the valve spring of the application valve is designed in such a way that the minimum selectable opening time is in a range of from 10 ms to 60 ms when there is a fluid pressure in a range of from 4 bar to 10 bar at the application valve and the dynamic viscosity of the fluid is in a range of from 25 mPa·s to 70 mPa·s. 
     
     
       7. The portable spraying device of  claim 1 , wherein the viscosity of the formulation to be dispensed can be detected and the opening time of the application valve can be controlled by the control device in accordance with the viscosity detected. 
     
     
       8. The portable spraying device of  claim 7 , wherein there is arranged in the container a temperature sensor coupled to the control device, and the control device is designed to calculate the viscosity of the formulation to be dispensed in accordance with the temperature measured by the temperature sensor. 
     
     
       9. The portable spraying device of  claim 1 , wherein the application valve has at least one electromagnet, by means of which it is possible to exert on the shutoff body a force for opening or closing the application valve counter to the force exerted by the valve spring. 
     
     
       10. The portable spraying device of  claim 1 , wherein the application valve is a plate armature valve. 
     
     
       11. The portable spraying device of  claim 1 , wherein, when closing the application valve, the shutoff body exerts on the fluid a pressure which is greater than the predetermined fluid pressure by a factor of at least 1.2. 
     
     
       12. The portable spraying device of  claim 1 , wherein the spray opening is arranged in a hollow-cone nozzle. 
     
     
       13. The portable spraying device of  claim 1 , wherein the pump is a self-priming pump. 
     
     
       14. The portable spraying device of  claim 1 , wherein the pump is an electric diaphragm pump. 
     
     
       15. The portable spraying device of  claim 1 , wherein a pulsation damper is arranged in the application line. 
     
     
       16. The portable spraying device of  claim 1 , wherein the spraying device has a switching device for setting an operating mode of the spraying device. 
     
     
       17. The portable spraying device of  claim 16 , wherein the control device is designed, in a first operating mode, to control the valve in such a way that it is in the first position, with the result that ambient air is pumped through the application line. 
     
     
       18. The portable spraying device of  claim 16 , wherein the control device is designed, in a second operating mode, to control the valve in such a way that it is in the second position, in which fluid is drawn in from the container, and that fluid is pumped continuously out of the container through the application line. 
     
     
       19. The portable spraying device of  claim 16 , wherein the control device is designed, in a second operating mode, to control the valve in such a way that it is in the second position, in which fluid is drawn in from the container, and to control the pump and the application valve in such a way that a defined volume of the fluid is discharged via the spray opening if the pressure sensor detects that the fluid pressure is above a threshold. 
     
     
       20. The portable spraying device of  claim 1 , wherein the weight of the spraying device when the container is empty is less than 15 kg. 
     
     
       21. The portable spraying device of  claim 1 , wherein the spraying device comprises a carrying system designed as a backpack. 
     
     
       22. The portable spraying device of  claim 1 , wherein the container can be fastened detachably to the spraying device, and the spraying device comprises a cap, by means of which a removal opening of the container can be closed fluid tightly, wherein a removal line passes fluid tightly through the cap, projecting with one end into the container and, at the other end, outside the container, having a coupling for coupling to a connecting line. 
     
     
       23. The portable spraying device of  claim 22 , wherein the container is held by the spraying device in such a way that the removal opening closed by the cap faces downward. 
     
     
       24. The portable spraying device of  claim 1 , wherein the spray gun is designed as a handheld part, and a fastening device for detachably fastening the application line to an arm of a user is arranged on the application line. 
     
     
       25. A portable spraying device for discharging a fluid, the portable spraying device comprising:
 a container for holding the fluid, 
 a pump, which is in fluid connection with the container, for pumping the fluid out of the container, 
 a spray gun, which comprises a spray opening and an electrically controllable application valve for opening and closing a passage to the spray opening, 
 an application line, which establishes a fluid connection between the pump and the spray gun, 
 a pressure sensor, which is arranged in the application line, for detecting the fluid pressure in the application line, 
 an electric control device, which is coupled to the application valve and the pressure sensor in terms of data transmission, wherein the electric device is adapted to deliver an electric control signal for opening the application valve for a certain predetermined time interval and for closing the application valve on expiry of the time interval in accordance with the fluid pressure detected by means of the pressure sensor, with the result that a defined volume of the fluid is discharged via the spray opening, and 
 an electrically controllable valve, which is arranged between the container and the pump, and which is coupled to the control device in terms of data transmission, wherein ambient air is drawn in by the pump in a first position of the valve, such that ambient air passes through the valve; and fluid is drawn in from the container in a second position of the valve, such that fluid passes through the valve.